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Before applying for CfA Telescope time, please check telescope and instrument availability below. Before applying for a PI instrument, contact the Principal Investigator and obtain a letter of approval to be submitted with your proposal.

First time users are expected to read the documentation and speak with the instrument PI if they have questions; the TAC chair can point people to recent users for practical tips.

COVID-19 update: MMT and FLWO staff are mostly vaccinated and the telescopes are returning to normal operation, however Magellan remains limited to one telescope (Baade or Clay) operation.  All of the observatories restrict outside visitors, which impacts PI instruments. The TAC encourages proposals for instruments that can be operated in service-observing, queue, or remote-observing modes, which is essentially every instrument except M2FS, PISCO, and MagAO.


  • 6.5m MMT telescope, located on Mt Hopkins in Arizona. Approximately 26 dark + 15 grey + 26 bright nights are available per 6 month semester; summer shutdown impacts July and August.

  • 6.5m Magellan telescopes, located on Las Campanas in Chile. Approximately 22 dark + 11 grey + 22 bright nights, evenly split between the two telescopes, are available per 6 month semester. Instruments are linked to a specific telescope.

  • Fred Lawrence Whipple Observatory (FLWO), located on Mt Hopkins in Arizona. The 1.2m telescope is dedicated to imaging; the 1.5m telescope is dedicated to spectroscopy. Approximately 72 dark + 36 grey + 72 bright nights are available on each telescope per 6 month semester, minus 30 nights in B semester due to August shutdown.


  • MMT and FLWO instruments are mostly run in queue mode, as indicated below. For instruments run in a queue, PI's submit their targets before the trimester begins; observations are scheduled and obtained by observers at the telescope.
  • Magellan instruments, with two exceptions, are not queue-scheduled. That said, a service observer is now available to CfA PIs; travel to Magellan is no longer required. The expectation is that the service observer will do the observing unless PIs choose otherwise.


1.2m FLWO Available? Queue?
Optical KeplerCam - CCD imager YES YES
1.5m FLWO Available? Queue?
Optical FAST - moderate dispersion single-slit spectrograph YES YES
  TRES - high dispersion single-fiber echelle spectrograph YES YES


6.5m MMT Available? Queue?
Optical Binospec - moderate dispersion multi-slit spectrograph and imager YES YES
  Hectospec - moderate dispersion 300-fiber spectrograph YES* YES
  Hectochelle - high dispersion 240-fiber echelle spectrograph YES* YES
  Blue Channel - moderate dispersion single-slit spectrograph YES no
  MMT Cam - small field-of-view imager YES YES
  SPOL - imaging spectropolarimeter Contact PI no
Near-IR MMIRS - multi-slit spectrograph and imager YES YES
  ARIES - adaptive optics imager and spectrograph no** no
  MMT-Pol - imaging polarimeter no** no

* Hectospec/chelle are not scheduled in Dec-Jan because of a low-temperature operational limit.

** MMT Adaptive Optics System is offline for upgrades; it is not expected to be available for proposals until 2023.


6.5m Magellan I = Baade Available? Queue?
Optical IMACS - moderate dispersion multi-slit spectrograph and imager YES no
  MagE - moderate dispersion single-slit echellette spectrograph YES no
Near-IR FourStar - wide-field imager YES no
  FIRE - high dispersion single-slit echelle spectrograph YES no
6.5m Magellan II = Clay    
Optical Megacam - wide-field imager YES no
  LDSS-3 - moderate dispersion multi-slit spectrograph YES no
  MIKE - high dispersion single-slit echelle spectrograph YES no
  M2FS - fiber fed multi-object spectrograph (planning) (reductions) Contact PI* YES
  PFS - high dispersion single-slit echelle spectrograph Contact PI YES
  PISCO - parallel imager no no
Near-IR MagAO - adaptive optics imager(s) Contact PI no

* Travel restrictions currently prohibit M2FS runs.

[Updated May 11, 2021 by WRB.]